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authorKay Sievers <kay@vrfy.org>2012-10-22 18:23:08 +0200
committerKay Sievers <kay@vrfy.org>2012-10-23 16:43:32 +0200
commit796b06c21b62d13c9021e2fbd9c58a5c6edb2764 (patch)
treef46dc94e7589364887b9bb91589010f41d29706d /src/udev/udevadm-hwdb.c
parent59bb9d9a14889bee001706a32a518fe0a5009048 (diff)
udev: add hardware database support
Diffstat (limited to 'src/udev/udevadm-hwdb.c')
-rw-r--r--src/udev/udevadm-hwdb.c548
1 files changed, 548 insertions, 0 deletions
diff --git a/src/udev/udevadm-hwdb.c b/src/udev/udevadm-hwdb.c
new file mode 100644
index 0000000000..52fe1d4ebc
--- /dev/null
+++ b/src/udev/udevadm-hwdb.c
@@ -0,0 +1,548 @@
+/***
+ This file is part of systemd.
+
+ Copyright 2012 Kay Sievers <kay.sievers@vrfy.org>
+
+ systemd is free software; you can redistribute it and/or modify it
+ under the terms of the GNU Lesser General Public License as published by
+ the Free Software Foundation; either version 2.1 of the License, or
+ (at your option) any later version.
+
+ systemd is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <stdlib.h>
+#include <unistd.h>
+#include <getopt.h>
+#include <string.h>
+
+#include "util.h"
+#include "strbuf.h"
+#include "conf-files.h"
+
+#include "udev.h"
+#include "udev-hwdb.h"
+
+/*
+ * Generic udev properties, key/value database based on modalias strings.
+ * Uses a Patricia/radix trie to index all matches for efficient lookup.
+ */
+
+static const char * const conf_file_dirs[] = {
+ SYSCONFDIR "/udev/hwdb.d",
+ UDEVLIBEXECDIR "/hwdb.d",
+ NULL
+};
+
+/* in-memory trie objects */
+struct trie {
+ struct trie_node *root;
+ struct strbuf *strings;
+
+ size_t nodes_count;
+ size_t children_count;
+ size_t values_count;
+};
+
+struct trie_node {
+ /* prefix, common part for all children of this node */
+ size_t prefix_off;
+
+ /* sorted array of pointers to children nodes */
+ struct trie_child_entry *children;
+ uint8_t children_count;
+
+ /* sorted array of key/value pairs */
+ struct trie_value_entry *values;
+ size_t values_count;
+};
+
+/* children array item with char (0-255) index */
+struct trie_child_entry {
+ uint8_t c;
+ struct trie_node *child;
+};
+
+/* value array item with key/value pairs */
+struct trie_value_entry {
+ size_t key_off;
+ size_t value_off;
+};
+
+static int trie_children_cmp(const void *v1, const void *v2) {
+ const struct trie_child_entry *n1 = v1;
+ const struct trie_child_entry *n2 = v2;
+
+ return n1->c - n2->c;
+}
+
+static int node_add_child(struct trie *trie, struct trie_node *node, struct trie_node *node_child, uint8_t c) {
+ struct trie_child_entry *child;
+ int err = 0;
+
+ /* extend array, add new entry, sort for bisection */
+ child = realloc(node->children, (node->children_count + 1) * sizeof(struct trie_child_entry));
+ if (!child) {
+ err = -ENOMEM;
+ goto out;
+ }
+ node->children = child;
+ trie->children_count++;
+ node->children[node->children_count].c = c;
+ node->children[node->children_count].child = node_child;
+ node->children_count++;
+ qsort(node->children, node->children_count, sizeof(struct trie_child_entry), trie_children_cmp);
+ trie->nodes_count++;
+out:
+ return err;
+}
+
+static struct trie_node *node_lookup(const struct trie_node *node, uint8_t c) {
+ struct trie_child_entry *child;
+ struct trie_child_entry search;
+
+ search.c = c;
+ child = bsearch(&search, node->children, node->children_count, sizeof(struct trie_child_entry), trie_children_cmp);
+ if (child)
+ return child->child;
+ return NULL;
+}
+
+static void trie_node_cleanup(struct trie_node *node) {
+ size_t i;
+
+ for (i = 0; i < node->children_count; i++)
+ trie_node_cleanup(node->children[i].child);
+ free(node->children);
+ free(node->values);
+ free(node);
+}
+
+static int trie_values_cmp(const void *v1, const void *v2, void *arg) {
+ const struct trie_value_entry *val1 = v1;
+ const struct trie_value_entry *val2 = v2;
+ struct trie *trie = arg;
+
+ return strcmp(trie->strings->buf + val1->key_off,
+ trie->strings->buf + val2->key_off);
+}
+
+static int trie_node_add_value(struct trie *trie, struct trie_node *node,
+ const char *key, const char *value) {
+ size_t k, v;
+ struct trie_value_entry *val;
+ struct trie_value_entry search;
+
+ k = strbuf_add_string(trie->strings, key, strlen(key));
+ v = strbuf_add_string(trie->strings, value, strlen(value));
+
+ /* replace existing earlier key with new value */
+ search.value_off = k;
+ val = xbsearch_r(&search, node->values, node->values_count, sizeof(struct trie_value_entry), trie_values_cmp, trie);
+ if (val) {
+ val->value_off = v;
+ return 0;
+ }
+
+ /* extend array, add new entry, sort for bisection */
+ val = realloc(node->values, (node->values_count + 1) * sizeof(struct trie_value_entry));
+ if (!val)
+ return -ENOMEM;
+ trie->values_count++;
+ node->values = val;
+ node->values[node->values_count].key_off = k;
+ node->values[node->values_count].value_off = v;
+ node->values_count++;
+ qsort_r(node->values, node->values_count, sizeof(struct trie_value_entry), trie_values_cmp, trie);
+ return 0;
+}
+
+static int trie_insert(struct trie *trie, struct trie_node *node, const char *search,
+ const char *key, const char *value) {
+ size_t i = 0;
+ int err = 0;
+
+ for (;;) {
+ size_t p;
+ uint8_t c;
+ struct trie_node *child;
+
+ for (p = 0; (c = trie->strings->buf[node->prefix_off + p]); p++) {
+ char *s;
+ ssize_t off;
+
+ if (c == search[i + p])
+ continue;
+
+ /* split node */
+ child = calloc(sizeof(struct trie_node), 1);
+ if (!child) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ /* move values from parent to child */
+ child->prefix_off = node->prefix_off + p+1;
+ child->children = node->children;
+ child->children_count = node->children_count;
+ child->values = node->values;
+ child->values_count = node->values_count;
+
+ /* update parent; use strdup() because the source gets realloc()d */
+ s = strndup(trie->strings->buf + node->prefix_off, p);
+ if (!s) {
+ err = -ENOMEM;
+ goto out;
+ }
+ off = strbuf_add_string(trie->strings, s, p);
+ free(s);
+ if (off < 0) {
+ err = off;
+ goto out;
+ }
+ node->prefix_off = off;
+ node->children = NULL;
+ node->children_count = 0;
+ node->values = NULL;
+ node->values_count = 0;
+ err = node_add_child(trie, node, child, c);
+ if (err)
+ goto out;
+ break;
+ }
+ i += p;
+
+ c = search[i];
+ if (c == '\0')
+ return trie_node_add_value(trie, node, key, value);
+
+ child = node_lookup(node, c);
+ if (!child) {
+ ssize_t off;
+
+ /* new child */
+ child = calloc(sizeof(struct trie_node), 1);
+ if (!child) {
+ err = -ENOMEM;
+ goto out;
+ }
+ off = strbuf_add_string(trie->strings, search + i+1, strlen(search + i+1));
+ if (off < 0) {
+ err = off;
+ goto out;
+ }
+ child->prefix_off = off;
+ err = node_add_child(trie, node, child, c);
+ if (err)
+ goto out;
+ return trie_node_add_value(trie, child, key, value);
+ }
+
+ node = child;
+ i++;
+ }
+out:
+ return err;
+}
+
+struct trie_f {
+ FILE *f;
+ struct trie *trie;
+ uint64_t strings_off;
+
+ uint64_t nodes_count;
+ uint64_t children_count;
+ uint64_t values_count;
+};
+
+/* calculate the storage space for the nodes, children arrays, value arrays */
+static void trie_store_nodes_size(struct trie_f *trie, struct trie_node *node) {
+ uint64_t i;
+
+ for (i = 0; i < node->children_count; i++)
+ trie_store_nodes_size(trie, node->children[i].child);
+
+ trie->strings_off += sizeof(struct trie_node_f);
+ for (i = 0; i < node->children_count; i++)
+ trie->strings_off += sizeof(struct trie_child_entry_f);
+ for (i = 0; i < node->values_count; i++)
+ trie->strings_off += sizeof(struct trie_value_entry_f);
+}
+
+static int64_t trie_store_nodes(struct trie_f *trie, struct trie_node *node) {
+ uint64_t i;
+ struct trie_node_f n = {
+ .prefix_off = htole64(trie->strings_off + node->prefix_off),
+ .children_count = node->children_count,
+ .values_count = htole64(node->values_count),
+ };
+ struct trie_child_entry_f *children;
+ int64_t node_off;
+
+ if (node->children_count) {
+ children = new0(struct trie_child_entry_f, node->children_count);
+ if (!children)
+ return -ENOMEM;
+ }
+
+ /* post-order recursion */
+ for (i = 0; i < node->children_count; i++) {
+ int64_t child_off;
+
+ child_off = trie_store_nodes(trie, node->children[i].child);
+ if (child_off < 0)
+ return child_off;
+ children[i].c = node->children[i].c;
+ children[i].child_off = htole64(child_off);
+ }
+
+ /* write node */
+ node_off = ftello(trie->f);
+ fwrite(&n, sizeof(struct trie_node_f), 1, trie->f);
+ trie->nodes_count++;
+
+ /* append children array */
+ if (node->children_count) {
+ fwrite(children, sizeof(struct trie_child_entry_f), node->children_count, trie->f);
+ trie->children_count += node->children_count;
+ free(children);
+ }
+
+ /* append values array */
+ for (i = 0; i < node->values_count; i++) {
+ struct trie_value_entry_f v = {
+ .key_off = htole64(trie->strings_off + node->values[i].key_off),
+ .value_off = htole64(trie->strings_off + node->values[i].value_off),
+ };
+
+ fwrite(&v, sizeof(struct trie_value_entry_f), 1, trie->f);
+ trie->values_count++;
+ }
+
+ return node_off;
+}
+
+static int trie_store(struct trie *trie, const char *filename) {
+ struct trie_f t = {
+ .trie = trie,
+ };
+ char *filename_tmp;
+ int64_t pos;
+ int64_t root_off;
+ int64_t size;
+ struct trie_header_f h = {
+ .signature = HWDB_SIG,
+ .tool_version = htole64(atoi(VERSION)),
+ .header_size = htole64(sizeof(struct trie_header_f)),
+ .node_size = htole64(sizeof(struct trie_node_f)),
+ .child_entry_size = htole64(sizeof(struct trie_child_entry_f)),
+ .value_entry_size = htole64(sizeof(struct trie_value_entry_f)),
+ };
+ int err;
+
+ /* calculate size of header, nodes, children entries, value entries */
+ t.strings_off = sizeof(struct trie_header_f);
+ trie_store_nodes_size(&t, trie->root);
+
+ err = fopen_temporary(filename , &t.f, &filename_tmp);
+ if (err < 0)
+ return err;
+ fchmod(fileno(t.f), 0444);
+
+ /* write nodes */
+ fseeko(t.f, sizeof(struct trie_header_f), SEEK_SET);
+ root_off = trie_store_nodes(&t, trie->root);
+ h.nodes_root_off = htole64(root_off);
+ pos = ftello(t.f);
+ h.nodes_len = htole64(pos - sizeof(struct trie_header_f));
+
+ /* write string buffer */
+ fwrite(trie->strings->buf, trie->strings->len, 1, t.f);
+ h.strings_len = htole64(trie->strings->len);
+
+ /* write header */
+ size = ftello(t.f);
+ h.file_size = htole64(size);
+ fseeko(t.f, 0, SEEK_SET);
+ fwrite(&h, sizeof(struct trie_header_f), 1, t.f);
+ err = ferror(t.f);
+ if (err)
+ err = -errno;
+ fclose(t.f);
+ if (err < 0 || rename(filename_tmp, filename) < 0) {
+ unlink(filename_tmp);
+ goto out;
+ }
+
+ log_debug("=== trie on-disk ===\n");
+ log_debug("size: %8zi bytes\n", size);
+ log_debug("header: %8zu bytes\n", sizeof(struct trie_header_f));
+ log_debug("nodes: %8zu bytes (%8zi)\n", t.nodes_count * sizeof(struct trie_node_f), t.nodes_count);
+ log_debug("child pointers: %8zu bytes (%8zi)\n", t.children_count * sizeof(struct trie_child_entry_f), t.children_count);
+ log_debug("value pointers: %8zu bytes (%8zi)\n", t.values_count * sizeof(struct trie_value_entry_f), t.values_count);
+ log_debug("string store: %8zu bytes\n", trie->strings->len);
+ log_debug("strings start: %8llu\n", (unsigned long long) t.strings_off);
+out:
+ free(filename_tmp);
+ return err;
+}
+
+static int import_file(struct trie *trie, const char *filename) {
+ FILE *f;
+ char line[LINE_MAX];
+ char match[LINE_MAX];
+
+ f = fopen(filename, "re");
+ if (f == NULL)
+ return -errno;
+
+ match[0] = '\0';
+ while (fgets(line, sizeof(line), f)) {
+ size_t len;
+
+ if (line[0] == '#')
+ continue;
+
+ /* new line, new record */
+ if (line[0] == '\n') {
+ match[0] = '\0';
+ continue;
+ }
+
+ /* remove newline */
+ len = strlen(line);
+ if (len < 2)
+ continue;
+ line[len-1] = '\0';
+
+ /* start of new record */
+ if (match[0] == '\0') {
+ strcpy(match, line);
+ continue;
+ }
+
+ /* value lines */
+ if (line[0] == ' ') {
+ char *value;
+
+ value = strchr(line, '=');
+ if (!value)
+ continue;
+ value[0] = '\0';
+ value++;
+ trie_insert(trie, trie->root, match, line, value);
+ }
+ }
+ fclose(f);
+ return 0;
+}
+
+static void help(void) {
+ printf("Usage: udevadm hwdb [--create] [--help]\n"
+ " --update update the hardware database\n"
+ " --help\n\n");
+}
+
+static int adm_hwdb(struct udev *udev, int argc, char *argv[]) {
+ static const struct option options[] = {
+ { "update", no_argument, NULL, 'u' },
+ { "help", no_argument, NULL, 'h' },
+ {}
+ };
+ bool update = false;
+ struct trie *trie;
+ char **files, **f;
+ int err;
+ int rc = EXIT_SUCCESS;
+
+ for (;;) {
+ int option;
+
+ option = getopt_long(argc, argv, "ch", options, NULL);
+ if (option == -1)
+ break;
+
+ switch (option) {
+ case 'u':
+ update = true;
+ break;
+ case 'h':
+ help();
+ return EXIT_SUCCESS;
+ }
+ }
+
+ if (!update) {
+ help();
+ return EXIT_SUCCESS;
+ }
+
+ trie = calloc(sizeof(struct trie), 1);
+ if (!trie) {
+ rc = EXIT_FAILURE;
+ goto out;
+ }
+
+ /* string store */
+ trie->strings = strbuf_new();
+ if (!trie->strings) {
+ rc = EXIT_FAILURE;
+ goto out;
+ }
+
+ /* index */
+ trie->root = calloc(sizeof(struct trie_node), 1);
+ if (!trie->root) {
+ rc = EXIT_FAILURE;
+ goto out;
+ }
+ trie->nodes_count++;
+
+ err = conf_files_list_strv(&files, ".hwdb", (const char **)conf_file_dirs);
+ if (err < 0) {
+ log_error("failed to enumerate hwdb files: %s\n", strerror(-err));
+ rc = EXIT_FAILURE;
+ goto out;
+ }
+ STRV_FOREACH(f, files) {
+ log_debug("reading file '%s'", *f);
+ import_file(trie, *f);
+ }
+ strv_free(files);
+
+ strbuf_complete(trie->strings);
+
+ log_debug("=== trie in-memory ===\n");
+ log_debug("nodes: %8zu bytes (%8zu)\n", trie->nodes_count * sizeof(struct trie_node), trie->nodes_count);
+ log_debug("children arrays: %8zu bytes (%8zu)\n", trie->children_count * sizeof(struct trie_child_entry), trie->children_count);
+ log_debug("values arrays: %8zu bytes (%8zu)\n", trie->values_count * sizeof(struct trie_value_entry), trie->values_count);
+ log_debug("strings: %8zu bytes\n", trie->strings->len);
+ log_debug("strings incoming: %8zu bytes (%8zu)\n", trie->strings->in_len, trie->strings->in_count);
+ log_debug("strings dedup'ed: %8zu bytes (%8zu)\n", trie->strings->dedup_len, trie->strings->dedup_count);
+
+ mkdir_parents(SYSCONFDIR "/udev/hwdb.bin", 0755);
+ err = trie_store(trie, SYSCONFDIR "/udev/hwdb.bin");
+ if (err < 0) {
+ log_error("Failure writing hardware database '%s': %s", SYSCONFDIR "/udev/hwdb.bin", strerror(-err));
+ rc = EXIT_FAILURE;
+ }
+
+out:
+ if (trie->root)
+ trie_node_cleanup(trie->root);
+ strbuf_cleanup(trie->strings);
+ free(trie);
+ return rc;
+}
+
+const struct udevadm_cmd udevadm_hwdb = {
+ .name = "hwdb",
+ .cmd = adm_hwdb,
+ .help = "maintain the hardware database index",
+};